Analysis Of Brain Functional Plasticity Under Training And Extreme Condition

As a specific attribute of the brain,the brain plasticity can help individuals to better suit for the changes of environment and life style.In addition,long-term training or living in the extreme condition have been widely considered to be the important factors leading to the brain structural and functional reorganization.In this study,based on the restingstate fMRI of taxi drivers and control group first,we examined the potential influence of long-term navigation training on the brain spatial processing and memory systems,by comparing the functional connectivity maps of entorhinal cortex and hippocampus between the two groups.Besides,we investigated the effects of long-term living in the closed and unsocial environment on the functional patterns of brain default mode network(DMN),by comparing the changes of DMN positive and negative functional connectivity between the crewmembers and controls.The main content of this paper is as follows:Examining the effects of long-term navigation training on the functional connectivity patterns of entorhinal cortex.The anterior-lateral(alEC)and posteriormedial(pmEC)subregion of entorhinal cortex are respectively involved in the encoding and conveying of spatial object and scene information.In this study,the alEC and pmEC were defined as the ROIs,and the functional connectivity differences between the taxi drivers and controls were examined.The results demonstrated that,the functional connectivity between the left pmEC and right anterior cingulate cortex,angular gyrus and bilateral precuneus,and the connectivity between the right pmEC and left inferior temporal gyrus were significantly reduced in the taxi drivers.Moreover,the connectivity strength between the left pmEC and the anterior cingulate cortex as well as the precuneus was negatively correlated with the taxi driving years,indicating the potential effects of long-term navigation training on the functional connectivity patterns of entorhinal cortex.Segmenting the hippocampus into functional subregions and comparing the functional connectivity of these subregions between the taxi drivers and controls.In this study,the bilateral hippocampus was functionally segmented into three subregions with the discriminative embedded clustering methods,and the functional connectivity differences of these subregions between the taxi drivers and controls were also examined.In our results,the significantly reduced functional connectivity between the posterior subregions and the superior frontal gyrus,orbitofrontal cortex as well as the caudate was observed,which was consistent with the results of entorhinal cortex analysis.Our results indicated that the long-term navigation training might contribute to the functional connectivity changes in the hippocampus,and might further influence the operating of spatial memory retrieving and route planning.Investigating the brain functional plasticity under long-term closed and unsocial conditions.Using a case-study method,we examined the changes of crewmembers' DMN positive and negative functional connectivity before and after a 180-day isolation experiment,from the voxel-wise level and network level,respectively.All the three crewmembers exhibited more significant changes of DMN functional connectivity compared with the normal controls,which might reveal the effects of longterm closed and unsocial conditions on the functional property of brain DMN.